A delicate spring-blooming perennial native to eastern North America, rue anemone (Thalictrum thalictroides) is well-suited to wildflower or woodland gardens. Part of the buttercup family (Ranunculaceae), it grows in clusters and is spread via its thin tuberous root system. From a low clump of small basal leaves, one to six flower stalks extends up in spring, each with a single small white flower that is sometimes tinged with pink. After flowering, this ephemeral plant goes dormant and dies back as the heat of the summer arrives.
Rue anemone is normally planted in spring from potted nursery plants or root divisions. (Seeds are usually planted in fall.) It is a slow-growing plant but will gradually spread to fill available space, creating a long-lived colony.
Although T. thalictroides is not specifically included on formal lists of toxic plants, it should be noted that all plants in the Ranunculaceae family contain protoanemonim, which is mildly toxic to humans and animals. Handling these plants can cause skin inflammation, and ingesting large quantities can cause a variety of digestive upset symptoms.
|Common Name||Rue anemone, windflower|
|Botanical Name||Thalictrum thalictroides (previously Anemonella thalictroides)|
|Plant Type||Herbaceous perennial|
|Mature Size||6–9 in. tall, 6–9 in. wide|
|Sun Exposure||Partial to full shade|
|Soil Type||Humus-rich and well-drained|
|Bloom Time||March through to early June|
|Flower Color||White or pale pink|
|Hardiness Zones||4–8 (USDA)|
|Native Area||Eastern North America|
|Toxicity||Possibly toxic to humans and animals|
Rue Anemone Care
These plants have a preference for loamy, well-drained soils that aren't too moist and slightly sandy in composition, and they should be kept out of direct sunlight. Though delicate in appearance, they will bloom in abundance during the spring months if given these conditions. Space plants about 1 foot apart. Rue anemone is low-lying, so take care when positioning it to ensure it isn't crowded out or overshadowed by taller plants that also emerge early. But it is fine to place it among woodland plants that emerge later, with leaves that spread to fill in the spaces vacated by this spring ephemeral.
This isn't a species suited to being grown in city environments. It isn't tolerant of heavy urban pollution, and it may not flower successfully in formal landscapes.
Given rue anemone is native to woodland areas of eastern North America, it shouldn't be a surprise that it prefers a shady spot. During the spring, it'll thrive in partial shade, but when it goes dormant, full shade isn't usually a problem for this plant.
This makes this species a great choice for planting under deciduous tree canopies. In the spring, they'll receive the dappled light they prefer to grow in. When they go dormant during the summer, they'll still survive when the tree canopy is at its thickest and doesn't offer much light to the ground below.
Rue anemone prefers loose, humus-rich loamy or sandy soils, but they can cope in a variety of soil types. It does need to be well-drained, though, as these plants don't do well in standing water or overly moist conditions. Ideally, the soil should be nearly neutral in pH, but slightly acidic or slightly alkaline soils are usually not a problem.
If they're planted under trees, the falling leaves and other rotting organic material will be of benefit. A thin layer of mulch can help to retain moisture in dry soils and will protect against late spring frosts.
Because rue anemones can cope without too much moisture, this species won't need a lot of additional watering, especially if the area has a covering of mulch. Rue anemone is fairly drought tolerant, but keeping them moderately moist will ensure the longest bloom period in spring. If the plant is too wet the tuber roots can begin to rot, and overly dry conditions can result in the plant going dormant earlier than normal.
Its drought tolerance is a benefit if the rue anemone is planted under large, well-established trees, which absorb a lot of the available moisture into their sprawling root systems.
Temperature and Humidity
Rue anemones, despite their delicate-looking appearance, are surprisingly hardy in their established range, zones 4 to 8. They can tolerate hard spring frosts and still produce blooms.
This plant isn't suited to being grown in areas that experience overly hot, sunny, and humid conditions.
A native wildflower, rue anemone requires no supplemental feeding if grown in suitable circumstances—well-draining humusy soil that is somewhat sandy. At most, a layer of compost applied as a mulch over the root zone in fall is sufficient.
Types of Rue Anemone
T. thalictroides is the only species in the Thalictrum genus, and other than the pure species, there is only one named cultivar widely available—'Rosea', which has pure pink flowers rather than the white blossoms of the species.
Propagating Rue Anemone
The rue anemone has clusters of small tuberous roots, which are easily divided to propagate new plants. It's best to wear gloves when handling this plant to avoid skin irritation. Here's how to propagate rue anemone:
- In early spring as the plants are just coming out of dormancy, carefully dig up the entire root clump with a trowel.
- Use the trowel or a garden knife to slice down through the root clump, dividing it into as many as eight pieces. There is no need to make sure each section has an eye—the plant will regrow from even the smallest of root pieces.
- Immediately replant the pieces so the roots are just buried, in moderately moist, humusy soil that is well draining. Water well after planting, then weekly until robust new growth is evident.
How to Grow Rue Anemone From Seed
Although it's easier to grow new plants from root division, it's possible to grow rue anemone from seeds collected in early summer. They'll need to fully dry out before sowing and can benefit from a cold stratification period. Either plant them in the fall, or keep them moist and a refrigerator for a few months before planting. You shouldn't expect any flowering in the first season following germination—it can take as much as three years for them to reach flowering maturity.
Volunteer plants that arise from self-seeding can also be dug up and transplanted to new locations. Do this in the spring as the volunteers are just emerging.
This hardy wildflower needs no winter protection against cold if planted in its established hardiness range (zones 4 to 8). Late fall can be a good time to apply a layer of compost over the plants to provide nutrients for the following spring.
Common Pests & Plant Diseases
This wildflower is often entirely trouble-free, but in moist conditions, it is sometimes susceptible to fungal diseases, such as powdery mildew, rust, and leaf smut. These diseases rarely kill the plant but can be controlled with fungicide sprays if desired. Rue anemone can also be a favorite food of slugs, which can be controlled by hand-picking or baiting.
These plants don't like extremely damp conditions, which may cause root rot.
How to Get Rue Anemone to Bloom
Rue anemone generally produces 1 to 6 flower stalks per plant, each stalk with one flower, during the spring. If they are not flowering in this way, there are several possible reasons:
- Plant is immature. These are slow-growing plants that can take several years before they flower. If you've just divided and replanted them, don't be surprised if they don't flower for a year or two.
- Not enough moisture. Though these plants are drought-tolerant, the flowering display is often reduced if the spring is uncharacteristically dry. Supplemental watering during early dry periods may ensure better flowering.
- Too much sun. These are shade-loving plants. Too much sun often inhibits flowering.
Common Problems With Rue Anemone
The most common complaint is not a problem, but rather the plant's natural behavior: It dies back as spring gives way to summer, leaving empty spots in the woodland garden. This is best remedied by planting rue anemone among other shade-loving perennials that fill out later in the season. such as hosta, lungwort, or Jacob's ladder.
How can I use rue anemone in the landscape?
This low-lying plant works well in shady borders or as a shady rock garden addition. It makes an excellent early spring wildflower for woodland or native plant gardens.
What is the difference between this plant and wood anemone, or false rue anemone?
This species is often confused with the wood anemone (Anemone quinquefolia) or the false rue anemone (Enemion biternatum), both of which grow during the spring in similar shady woodland habitats.
The rue anemone, however, has more petals on its flowers (usually around six to nine), and the three-lobed leaves are arranged in rounded, smooth whorls. The wood anemone, on the other hand, has distinctly serrated, tooth-like foliage.
Why is this plant called "anemone"?
Rue anemone bears a resemblance to two common native plants: The foliage resembles that of meadow rue (Thalictrum spp), while the flowers resemble those of species in the Anemone genus. As a result, it is known by a common name that incorporates both look-alikes.
Plants Poisonous to Livestock. Cornell College of Agriculture and Life Sciences.
Bird, Richard. Thalictrum. The Propagation of Hardy Perennials. Batsford Publishing, 1994.